Wednesday, July 29, 2015

Zebra mussels kill-off worked

WINNIPEG—Manitoba has declared victory in its first battle with invading zebra mussels, but says the unique treatment it used to kill the shellfish doesn’t mean the province is free of them yet.
The province sealed off four harbours in mid-May with a silt curtain before injecting liquid potash into the water.

The concentration of potash was increased until it suffocated the mussels.
The experiment received global attention because it’s believed to be the first time liquid potash has been used in open water.
Scientists who study the mussels called it a “golden opportunity” to find a way to prevent their proliferation in water bodies around the world.
Conservation minister Gord Mackintosh said the treatment was successful and killed the mussels in the harbours.
But it was just the first step in the fight to keep the mussels out of the province, he added.
“We’ve won the first battle in what is likely to be a long war and it must be a hard-fought war,” Mackintosh stressed yesterday.
“There is a good chance that zebra mussels are still lurking outside of the treated harbour areas,” he noted.
“We have got to detect wherever else these zebra mussels might be.”
The invasive species, which has been in the Great Lakes for almost two decades and has spread throughout parts of the U.S., was discovered for the first time in Manitoba last October.
The mussels reproduce quickly and can disrupt the food chain, clog water pipes, and create algae.
Mackintosh said the success of Manitoba’s experimental treatment has attracted worldwide attention from countries such as the U.S. and Spain.
He added the province hasn’t ruled out using the treatment—which cost $500,000—again.
For now, the province is increasing monitoring on Lake Winnipeg.
There also are five decontamination units for boats that could spread the mussels.
“It’s been estimated that about 90 percent of the boats coming into Manitoba come from jurisdictions where there is exposure to invasive species,” Mackintosh said. “So there is a great risk all around us.”
He implored boaters and residents to watch for the mussels and to ensure they aren’t unwittingly unleashed into Manitoba’s waterways.

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